A delivery device of this type for sheet-fed rotary printing machines is disclosed in DE 24 30 212 A1. The delivery device has a sorting device, which delivers printed copies selectively to two delivery stacks. The printed copies are subject to measurement-related quality control within the printing machine. A rotating first chain conveyor supplies the printed copies to a first delivery stack. A removal drum with gripper systems is allocated to the first chain conveyor. A second chain conveyor is arranged after the removal drum. Depending on the determined quality, the printed copies can be deposited on the first or second delivery stack.
DE 198 19 491 C1 discloses a sheet delivery unit for a rotary printing machine with an endlessly rotating feeding system supplying the sheets to a first delivery stack and with a drum acting as a turnout point before the delivery stack and featuring at least one gripper system. The drum is used for selective or constant sheet removal and is allocated to the lower track of the feeding system. For the purpose of delivering the sheets, a second stacking system is arranged adjacent to the drum. Outside the lower track, a sheet guidance device is arranged with an opening extending across the format width. The gripper system of the drum intersects the opening with its orbit and the second stacking system is arranged approximately underneath the drum. The second stacking system can be embodied as a pallet or screen box, e.g., for removing spoiled sheets, and also as a stacking system with stopping and jogging elements for forming exact stacks.
Another delivery unit for a sheet-fed rotary printing machine is disclosed in DE 198 19 490 C1. This delivery device has several sheet feeding systems, with a transfer cylinder being arranged between a first and a second sheet feeding system. A first stacking system (main stack) is allocated to the second sheet feeding system and a second stacking system (deep stack) is allocated to the transfer cylinder. A third sheet feeding system running above the second sheet feeding system leads from the transfer cylinder to a storage area for sheets. A measurement device, which preferably is moveable, is allocated to this storage area for scanning the top side of a sheet.
A disadvantage of this arrangement is that the second stacking system can be used only for storing spoiled sheets or for the temporary storage of sheets during nonstop stack alternating in the first stacking system.